The present invention relates to a method of producing a substantially-virus-inactivated protein-containing composition from a protein-containing composition which may be contaminated with virus.
There is a possibility that compositions containing human-blood-derived protein may be contaminated with viruses, e.g., hepatitis virus and AIDS virus.
There are some known methods in which a protein-containing liquid composition is heated to prevent transmission of these viruses (Unexamined Japanese Patent Application Laid Open Nos. 145615/1980 corresponding to U.S. Pat. No. 4,297,344 and EP Publication No. 18561; 139422/1981 corresponding to U.S. Pat. No. 4,440,679 and EP Publication No. 35204; and 106594/1981 corresponding to U.S. Pat. No. 4,361,652 and DE-3102217).
Also known is a method in which a protein-containing dry composition is heated [Published Japanese Translation of PCT Patent Application from Other Country (KOHYO) No. 500548/1983 corresponding to U.S. Pat. No. 4,495,278 and EP Publication No. 77355; and Unexamined Japanese Patent Application Laid Open No. 213721/1983 corresponding to U.S. Pat. No. 4,556,558 and EP Publication No. 171506.].
Another method is known in which a protein-containing composition is brought into contact with trialkyl phosphate to remove viruses (Unexamined Japanese Patent Application Laid Open No. 51116/1985 corresponding to U.S. Pat. No. 4,540,573 and EP Publication No. 131740).
However, highly heat resistant viruses may remain active through heat treatment and non-envelope viruses may remain active through trialkyl phosphate treatment.
Also, conventional methods have been faulty in that the protein activity decreases during trialkyl phosphate treatment.
The object of the present invention is to provide a method of efficiently inactivating contaminant viruses almost without spoiling the protein activity and thus producing a pharmaceutically safer protein-containing composition.